Recently, the Supreme Court directed Himachal Pradesh to release water to alleviate Delhi’s water shortage during a heatwave.
Delhi’s water source
Water dependency- Delhi depends on neighboring states to meet around 50 per cent of drinking water demand of its residents.
Semi-arid zone- The city, being located in a semi-arid zone, depends to a great extent on raw waters from the Ganga basin, Yamuna sub-basin, Indus-basin, in addition to its own internal aquifers and its groundwater resources.
Major rivers- Delhi gets most of its water from the Yamuna, Ravi-Beas, and Ganga rivers.
Ganga- Through Upper Ganga Canal in UP, Delhi receives 470 cusecs (roughly 254 MGD) of water.
River channels-Two channels entering Delhi from Haryana the Carrier Lined Channel (CLC) and the Delhi Sub Branch (DSB) supply Delhi with water from the Yamuna and Ravi-Beas rivers.
Water capacity- Delhi receives 719 cusecs of water through CLC, a lined channel meant to reduce seepage- induced water loss, and 330 cusecs through the DSB.
Delhi Jal Board- It takes water directly from Yamuna to try and meet demand.
It supplements its river- water supply with ground water around 135 MGD of which are drawn from Delhi’s tubewells and ranney wells.
Delhi is not allotted any specific amount of water it can draw directly from the river.
What triggered Delhi’s water shortage?
Under performance-The water treatment plant (WTP) in North Delhi’s Wazirabad was functioning below its capacity.
It is the third largest of DJB’s nine WTPs in terms of capacity, and primarily depends on water from the CLC and DSB.
High temperature- Delhi experienced record high temperatures, and thus, a steep surge in demand for water.
Electricity issues- Some water treatment plants also dealt with short power failures.
Lesser capability- DJB is not capable of meeting the city’s requirement of 1290 MGD during peak summers as estimated by the Economic Survey for 2023-24.
Rainfall deficits: Across the states of Himachal Pradesh, Punjab, Haryana, and Delhi recorded large rainfall deficits according to the India Meteorological Department (IMD).
Scant rainfall meant that the Yamuna simply did not have enough water for the DJB to draw from the Wazirabad reservoir.
Transit losses- Watercan be lost during transit due to seepage, evaporation, or other factors. These losses contribute to a decrease in the overall availability of water for distribution.
Infrastructure deficit- The infrastructure for water treatment, storage, and distribution in Delhi may face challenges such as leaks, inefficiencies, or insufficient capacity, further exacerbating water shortages during periods of high demand.
Inter-State dispute-Delhi accuses Haryana of inadequate water supply, while Haryana officials attribute the shortfall to higher evaporation due to severe heat.
Water allocation from Yamuna
A water sharing agreement on the surface flow of the Yamuna among Haryana, Uttar Pradesh, Rajasthan, Himachal Pradesh and Delhi in 1994, specified that Delhi is to get 0.076 billion cubic metres of water from March to June.
The annual allocation for Delhi is 0.724 BCM. This amounts to roughly 435 MGD.
This allocation is regulated by the Upper Yamuna River Board, with the 1994 agreement due for revision in 2025.
In 1996, the Supreme Court ordered that Delhi must receive sufficient water from Haryana via the Yamuna River to keep the Wazirabad and Hyderpur reservoirs full for domestic use.
What lies ahead?
The Delhi government has implemented measures such as operating tube wells round the clock and deploying water tankers to cater to the affected regions grappling with water scarcity.
A blanket ban on the use of potable water at construction sites has been enforced to conserve this precious resource.
A central water tanker control room is made and the deployment of quick response teams across all 11 Delhi Jal Board zones to tackle water-related emergencies effectively.
But the daily rush to collect water, especially amid the ongoing heatwave, is not a peaceful process and fights among residents are common.
